Medical device with an energy supply having at least two energy sources

ABSTRACT

According to one embodiment, a medical device may include an energy supply. The energy supply may include a lithium-ion polymer battery including at least two battery stacks and a control unit. One of the at least two battery stacks may be a backup energy source. The control unit may monitor and control the energy supply such that when the control unit detects a fault in the at least two battery stacks, the control unit disconnects a faulty battery stack. The energy supply may be rechargeable. Each of the at least two battery stacks may include a positive potential terminal, a negative potential terminal and one or more battery cell.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/878,074, filed Sep. 9, 2010, which is a continuation of InternationalApplication No. PCT/EP2009/001596 filed Mar. 6, 2009, which claimspriority to European Patent Application No. EP08004343.3 filed on Mar.10, 2008, both of which are herein incorporated by reference in theirentirety.

The present application is related to U.S. patent application Ser. No.12/878,071 filed Sep. 9, 2010, and entitled “MEDICAL DEVICE WITH ANENERGY SUPPLY CARRYING A RESERVOIR” which is herein incorporated byreference.

TECHNICAL FIELD

The present disclosure relates to medical devices and medical systems.In particular, the embodiments described herein relate to medicaldevices and medical systems for diabetes treatment comprising areservoir.

BACKGROUND

Portable medical devices may be powered by non-rechargeable batteries.

For example, WO 2000/52807 A1, which is incorporated by referenceherein, discloses a battery pack comprising a plurality of batterycells, each of them constituting an energy source. Depleted batterycells can be switched with charged battery cells via a battery switchingcircuit when the monitored voltage falls below a predetermined level.

EP 0982830 A2, which is incorporated by reference herein, discloses abattery pack with a plurality of cells which are, together with aprotective circuit, encased in a container. The protective circuitcomprises a cell failure detector for each of the cells and a cellinterrupter to disconnect a faulty cell.

Accordingly, additional medical devices and medical systems comprising arechargeable energy supply that is less susceptible to failure, whichmay be colloquially termed “fail safe” or “single fault safe,” areneeded.

SUMMARY

According to one embodiment, a medical device may include an energysupply. The energy supply may include a lithium-ion polymer batteryincluding at least two battery stacks and a control unit. One of the atleast two battery stacks may be a backup energy source. The control unitmay monitor and control the energy supply such that when the controlunit detects a fault in the at least two battery stacks, the controlunit disconnects a faulty battery stack. The energy supply may berechargeable. Each of the at least two battery stacks may include apositive potential terminal, a negative potential terminal and one ormore battery cell.

In another embodiment, a medical system may include an energy supply, acharging station for charging the energy supply and a medical device.The energy supply may be rechargeable. The energy supply includes alithium-ion polymer battery including at least two battery stacks. Oneof the at least two battery stacks may be a backup energy source. Eachof the at least two battery stacks may include a positive potentialterminal, a negative potential terminal and one or more battery cell.The medical device may include a control unit that monitors and controlsthe energy supply such that when the control unit detects a fault in theat least two battery stacks, the control unit disconnects a faultybattery stack. The charging station may include an USB-plug, a lineconnector, a solar cell panel, a primary battery, a plug for a carcigarette lighter outlet, a connector for a mobile phone accumulator, adynamo, or a combination thereof for supplying energy.

These and additional features provided by the embodiments describedherein will be more fully understood in view of the following detaileddescription, in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments set forth in the drawings are illustrative and exemplaryin nature and not intended to limit the subject matter defined by theclaims. The following detailed description of the illustrativeembodiments can be understood when read in conjunction with thefollowing drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 schematically depicts a medical device according to one or moreof the embodiments shown and described herein;

FIG. 2 schematically depicts a medical device according to one or moreof the embodiments shown and described herein;

FIG. 3 schematically depicts an energy supply according to one or moreof the embodiments shown and described herein;

FIG. 4 schematically depicts an energy supply supporting a reservoir fora fluid according to one or more of the embodiments shown and describedherein;

FIG. 5 schematically depicts an energy supply with two energy sourcesaccording to one or more of the embodiments shown and described herein;

FIG. 6 schematically depicts an energy supply with two energy sourcesaccording to one or more of the embodiments shown and described herein,

FIG. 7 schematically depicts an energy supply with two energy sourcesaccording to one or more of the embodiments shown and described herein;

FIG. 8 schematically depicts an energy supply with two energy sourcesaccording to one or more of the embodiments shown and described herein;

FIG. 9 depicts a block diagram of a medical device according to one ormore of the embodiments shown and described herein; and

FIG. 10 schematically depicts a charging station of a medical systemaccording to one or more of the embodiments shown and described herein.

DETAILED DESCRIPTION

According to the embodiments described herein, a medical devicecomprising an energy supply and a control unit for monitoring andcontrolling the energy supply is provided. The energy supply maycomprise at least two energy sources. The at least two energy sourcescomprise a backup energy source. The backup energy source may be usedfor supplying energy in cases where no backup is needed for the other ofthe at least two energy sources. The control unit can detect a fault inthe energy sources and can disconnect the faulty energy source uponfault detection.

Therefore, the embodiments described herein may operate as a redundantsystem that can be colloquially termed “fail-safe” or “single faultsafe.” For example, if one of the energy sources fails then one of theother energy sources functions as a backup energy source. The backupenergy source may take over the function of the faulty energy source orprovide enough energy to serve as an emergency energy supply fortriggering an alarm. Thus, fail-safe operation of the medical device isprovided even if a fault occurs in one of the energy sources of theenergy supply.

In one embodiment, the control unit comprises means for measuring andevaluating the output voltage and/or current of each energy source andmeans for disconnecting each energy source from the rest of the medicaldevice, i.e. the load of the energy supply. For example, the controlunit may comprise a control subunit for each energy source. Each controlsubunit comprises means for measuring and evaluating the output voltageand/or current of an associated energy source and means fordisconnecting the associated energy source from the load. For a medicaldevice such as an insulin pump, the load is the pump.

In another embodiment the energy supply is rechargeable and comprises alithium-ion polymer battery with at least two of the battery stacks.Lithium-ion polymer batteries are also commonly referred to as lithiumpolymer batteries or polymer lithium ion batteries. However, forconvenience the term lithium-ion polymer battery is used herein ratherthan listing all of the nomenclatures for such batteries and theirequivalents. Each battery stack operates as one energy source andcomprises a terminal or contact of positive potential and a terminal orcontact of negative potential. Each battery stack may furthermorecomprise one or more battery cells such as, for example, one or morebattery bi-cells. As used herein the term “bi-cell” means a cell withone anode and two cathodes, the cathodes being positioned on eithersides of the anode. The height of a bi-cell may be, for example, in therange of 600 to 800 micrometers.

Lithium-ion polymer batteries may be robust to physical damage and canbe cost-efficiently manufactured. Furthermore, lithium-ion polymerbatteries may be rechargeable, i.e. once the original energy supply hasbeen discharged the energy supply may be substantially restored. Theenergy provided by a lithium-ion polymer battery per volume isrelatively high, which may broaden application and/or device integrationpossibilities and possibly prolong running time. Due to their polymericnature, lithium-ion polymer batteries do not require a rigid casing andcan be specifically shaped to fit into a space such as within a medicaldevice. Specifically, a lithium-ion battery can be shaped to match andsubstantially fill a space provided by a medical device for an energysource. Therefore, for a given shape, a relatively high energy sourcecapacity can be provided. Furthermore, lithium-ion polymer batteries canbe manufactured to be relatively thin to correspond to a relatively thinmedical device configured to be discreetly employed or used by a usersuch as an insulin pump. Further, since lithium-ion polymer batterieshave a relatively low gravimetric density, the weight of the medicaldevice can be reduced, leading to an easier-to-carry medical device.Also due to their relatively high volumetric density, lithium-ionpolymer batteries may provide a relatively long running time for theenergy supply of the medical device. Lithium-ion polymer batteries havea relatively small internal resistance and are generally robust, i.e.tolerant, with respect to temperature and power variations. Since thecell-voltage and the discharge voltage range (typically 4.2 Volt-3.0Volt) of a lithium-ion polymer battery are relatively high, the energysupply and the energy source, respectively, have relatively lowsusceptibility to contamination of their terminals or contacts.

In one embodiment, the medical device is a portable device that may becontinuously carried by a user where it may be desirable to operate in afail-safe or single fault safe manner, such as an insulin pump. When themedical device comprises an energy supply with a lithium-ion polymerbattery having at least two battery stacks, the energy supply may becompact, exchangeable, rechargeable, or combinations thereof as onecompact unit.

Medical systems are provided by the embodiments described herein, themedical system comprising a medical device as described herein and acharging station for an energy supply of a medical device as describedherein.

In one embodiment, the charging station comprises an energy supplyingmeans such as, for example, an USB-plug, a line connector (also callednetwork connector), a solar cell panel, a primary battery, a plus for acar cigarette lighter outlet, a connector for a mobile phoneaccumulator, a dynamo with a crank handle, or a combination thereof. Forexample, a charging station may comprise at least two different energysupplying means. By providing several different types of energysupplying means, the charging station is not restricted to one type ofenergy (e.g. a primary battery) but can switch to a different kind ofenergy, in particular to a different kind of primary energy, (e.g. solarenergy or the energy provided by a car battery via a cigarette lighteroutlet) which is available at that moment. The energy switchingcapability may increase energy independence and reduce cost, whileproviding a substantially consistent and substantially uninterruptedenergy supply. For example, energy may be available in non-everydaysituations such as during vacation, during travel or in free time.Hence, charging stations according to the embodiments described hereinmay enhance user individuality and flexibility. The user can charge theenergy supply of his medical device as needed and according to his needsand according to the availability of energy resources. The embodimentsdescribed herein may adapt with outer circumstances such as, forexample, while in the office the line connector or the USB-plug may beutilized, while on vacation the solar energy may be utilized or thedynamo may be utilized by rotating the crank handle, and so on.

Medical dosing devices are provided herein such as, for example, insulinpumps.

According to one embodiment, FIG. 1 schematically depicts a medicaldevice 1.1 comprising a top cover 2. The top cover 2 forms part of thehousing 3.1 of the medical device 1.1. The top cover 2 may be mountedpivotally to the housing 3.1 on hinges 6. The medical device 1.1comprises a compartment 4 for an energy supply 5.1 which is replaceable.The replacement capability of the energy supply 5.1 is generallyindicated in FIG. 1 by a bent arrow. As depicted in FIG. 1, the energysupply 5.1 can be placed in the compartment 4 within the housing 3.1 ofthe medical device 1.1. No specific sealing functions have to beperformed between the outer surfaces of the energy supply 5.1 and thecompartment 4. Therefore, no specific sealing or gaskets have to beprovided at the contact surfaces of the energy supply 5.1 and thecompartment 4. The top cover 2 or the housing 3.1 may be sealed. Forexample, gaskets 39 or other sealing devices may be used to seal the topcover 2 or the housing 3.1. Furthermore, gaskets 38 may be arranged atcontact surfaces of the compartment 4 for sealing.

FIG. 2 schematically depicts another embodiment of a medical device 1.2comprising an energy supply 5.2 that is replaceable. The dashed arrowgenerally indicates the motion of an energy supply 5.2 as it isexchanged. As depicted in FIG. 2, a portion of the housing 3.2 of themedical device 1.2 is formed by an energy supply housing 7 for theenergy supply 5.2. The energy supply 5.2 comprises terminals 9 (orcontacts) and a contact surface 8 that forms an outer surface with theterminals 9. For sealing purposes, the contact surface 8 may be providedwith a sealing device, such as, for example, one or more gaskets. Thesealing device may, protect the medical device 1.2 against humidity,i.e., by sealing the terminals 9. While only two of the terminals 9 aredepicted in FIG. 2, it is noted that the energy supply 5.2 may compriseany number of terminals. Furthermore, it is noted that the embodimentsdescribed herein may be sealed such that the medical device 1.2 conformsto IPX8 (international protection rating X8), i.e. the medical device1.2 is protected against harmful ingress of water up to and beyond 1meter. Thus, the medical device 1.2 may be suitable for continuousimmersion in water under conditions which shall be specified by themanufacturer as described at the following URLhttp://en.wikipedia.org/wiki/IP_Code), which is incorporated byreference herein.

Referring now to FIG. 3, an energy supply 5.3 according to theembodiments described herein is schematically depicted The energy supply5.3 comprises a rechargeable lithium-ion polymer battery with, forexample, a nominal cell voltage of 3.7 Volt. The energy supply 5.3furthermore comprises a fuel gauge unit 10 for estimating and monitoringits remaining running time and/or life time. As used herein the term“fuel” means the charge of the energy supply 5.3 or the energy which canbe provided by the energy supply 5.3. The fuel gauge unit 10 determinesthe remaining running time via energy or impedance measuring. Forexample, the fuel gauge unit 10 may comprise so-called “smart”electronics.

Due to a laminated design, the lithium-ion polymer battery may consistof several battery cells, in particular bi-cells. Two or more batterystacks, each consisting of battery cells, may be integrated asindependent energy sources in one replaceable unit such as the energysupply 5.3. For example, referring collectively to FIGS. 3 and 5 through8, the lithium-ion polymer battery may comprise two of the batterystacks 11 with each of the battery stacks 11 representing one energysource. Each of the battery stacks 11 has a terminal 9 of positivepotential and a terminal 9 of negative potential. Thus, there aretherefore four terminals 9 with two of the battery stacks 11.Furthermore, each of the battery stacks 11 is provided with a protectioncircuit 12 for protection against overcharge, over-voltage,under-voltage, or combinations thereof. There can be provided one of thefuel gauge units 10 for the entire energy supply 5.3 or one of the fuelgauge units 10 allotted to each of the battery stacks 11. The fuel gaugeunit 10 and the protection circuit 12 may be enclosed by the energysupply housing 7 (not depicted in FIG. 3) and integrated in the energysupply 5.3.

Medical devices, according to the embodiments described herein, maycomprise a reservoir for a fluid which is carried by an energy supply.For example, a medical device such as an insulin pump typicallycomprises a reservoir such as a cartridge for insulin. FIG. 4 depicts anenergy supply 5.4, according to the embodiments described herein,comprising a cavity 13 for accommodating a reservoir 14. The cavity 13may be formed to accommodate a reservoir 14 that is cylindrically shapedsuch as a cartridge of an insulin pump. The reservoir 14 can be formedat least in part by the housing of the energy supply 5.4, e.g., thereservoir may be enclosed by or may be held and supported by the housingof the energy supply 5.4.

In another embodiment, the energy supply 5.4 carries components of amedical device, e.g., one or more glucose test strips or a test stripdrum. The energy supply 5.4, the reservoir 14, and other components canbe assembled outside the medical device. After assembly, the assembledcomponents can be inserted as one unit into the medical device. Forexample, the reservoir 14 (e.g., a cartridge, a pouch or a bag) can beplaced in the cavity 13 before the energy supply 5.4 is inserted intothe medical device. If the cavity 13 is formed by the housing of theenergy supply 5.4, the housing also serves as support for the reservoir14 in addition to constituting housing for the energy supply 5.4.

In other embodiments the reservoir (and/or other components of themedical device) may carry and support the energy supply.

In addition to combining the reservoir for fluid and the energy supplycomprising fuel gauge unit(s) and protection circuit(s) into one unit,the interfaces for fluid and for electric energy may also combined inthe one unit for sealing purposes. In one embodiment, the capacity ofthe reservoir and the running time of the energy supply aretime-synchronized. A change or refill of the reservoir may besubstantially coincident in time with a required change or recharge ofthe energy supply. For example, the remaining running time of the energysupply may be estimated by the fuel gauge unit. Hence, the therapeutichandling operation of reservoir refill or exchange can be combined withthe technical handling operation of energy supply exchange or recharge.

FIGS. 5 to 8 depict energy supplies according to the embodimentsdescribed herein. The energy supply housing 7 is generally depicted inFIGS. 5 to 8 dashed elliptical for simplicity and not by way oflimitation. Although not depicted in FIGS. 5 to 8 as touching, it isnoted that the terminals 9 of the battery stacks 11 are connected tocorresponding contacts 18 of the energy supply housing 7 (wherecorrespondence is indicated by “+” for positive potential and “−” fornegative potential).

FIG. 5 depicts an energy supply 5.5 comprising a rechargeablelithium-ion polymer-battery with at least two of the battery stacks 11as energy sources as described above. Each of the battery stacks 11comprises a cover 15. The cover 15 may be made of laminated aluminumfoil. The battery stacks 11 are placed on top of each other within theenergy supply housing 7. The energy supply housing 7 may be, made ofplastics. In one embodiment, the energy supply 5.5 is fully redundant,i.e., the battery stacks 11 and their covers 15 are equally structured.It is noted that, there can be one of the fuel gauge units 10 for theentire energy supply 5.5 or there can be one of the fuel gauge units foreach of the battery stacks 11. The fuel gauge unit 10 and the protectioncircuit 12 may be enclosed by the energy supply housing 7 and integratedin the energy supply 5.5.

In another embodiment, schematically depicted in FIG. 6, the energysupply 5.6 comprises two of the battery stacks 11 that are enclosed byone common cover 16, which may be made of laminated aluminum foil. Thisembodiment may also be referred to as quasi redundant.

In a further embodiment, schematically depicted in FIG. 7, the energysupply 5.7 comprises battery stacks 11 that are separated by a sealingsheet 17, which may be made of laminated aluminum foil. This embodimentmay also be referred to as quasi redundant. In FIG. 7 the battery stacks11 are depicted as being separated by one layer (the sealing sheet 17),while in FIG. 5 the battery stacks are depicted as being separated bytwo layers (twice the cover 15). Therefore, the quasi redundantembodiments, as schematically depicted in FIG. 7, need less space thanthe fully redundant embodiments, as schematically depicted in FIG. 5.

Referring now to FIG. 8, in one embodiment of the energy supply 5.8,each of the terminals 9 of negative potential of the battery stacks 11are connected to one common terminal 19 of negative potential. Theenergy supply housing 7 comprises contacts 18 that correspond and areconnected to the terminals 9 of positive potential and to the one commonterminal 19 of negative potential. Accordingly, a connection of theterminals 9 of negative potential to form one common terminal 19 ofnegative potential may be made in any of the embodiments describedherein.

It is noted that while the battery stacks 11 are depicted in FIGS. 5 to8 as being placed on top of one another, the battery stacks 11 can bearranged differently, for example, next to each other. Furthermore, itis noted that any of the features of the depicted energy supplies ofFIGS. 1 to 8 may be combined in embodiments having all possiblecombinations.

Referring collectively to FIGS. 1 to 8, the contacts 18 of the energysupply housing 7 may be connected to the terminals 9 or the one commonterminal 19 of the battery stacks 11. The contacts 18 represent theelectrical interface of the energy supply 5.1 to 5.8. The output voltageand/or current of the contacts 18 may be monitored periodically for thedetection of faults of the battery stacks 11, for example, within amultiple error occurrence period. Once a fault is detected, each of thebattery stacks 11 having the fault may be switched off, i.e.,disconnected, and its function may be taken over by the other of thebattery stacks 11. The multiple error occurrence period is defined asthe period of time, in which the probability for the occurrence ofmultiple faults that are safety critical is sufficiently small for aparticular requirement class. The multiple error occurrence periodstarts at the last point in time where the monitored device/system is ina fault-free state according to the considered requirement class. Thefault detection in one of the battery stacks may cause switching to abattery stack 11, without a fault, that may ensure safe operation for atime period that is long enough to trigger and/or produce an alarm, forexample, an alarm for a given time.

Referring now to FIG. 9, a schematic block diagram of a medical device1.3 is depicted, according to the embodiments described herein such as,for example, medical device 1.1 (FIG. 1) and medical device 1.2 (FIG.2). The medical device 1.3 comprises an energy supply 5.9 such as, forexample, energy supplies 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.8 (FIGS. 1 to8). The energy supply 5.9 comprises a rechargeable lithium-ion polymerbattery with two of the battery stacks 11. Each of the battery stacks 11is provided with a protection circuit 12. The energy supply 5.9 suppliesenergy to a load 20, e.g., a pump in an insulin pump medical device. Theload 20 can comprise several sub-loads. A control unit 21 is providedwith a control subunit 22 for each of the battery stacks 11. Although,the control subunits 22 are depicted in FIG. 9 as integrated in one unitas control unit 21 (generally indicated by the dashed box), the controlsubunits 22 may be separate units. Each of the control subunits 22comprises means for measuring and evaluating (not shown in FIG. 9) theoutput voltage and/or current of the battery stack 11 it is allotted toand a disconnecting means 23 for disconnecting the battery stack 11 fromthe load 20. The means for measuring and evaluating may comprise ananalog sensor for measuring the output voltage and/or current. Theanalog measurement signal is then converted by an analog-digitalconverter 24 of the control subunit 22 into a digital signal which canthen be evaluated by the disconnecting means 23 or another evaluationcircuit. The disconnecting means 23 for disconnecting the battery stack11 may control a switch 25 in the electrical path 26 from the batterystack 11 to the load 20. The control unit 21 may also comprise the fuelgauge unit(s) 10 (not shown in FIG. 9) and the protection circuit(s) 12,for example, when used with a fix installed lithium-ion polymer battery.

If the means for measuring and evaluating of one of the control subunits22 detects a fault in the battery stack 11 it is allotted to, then thedisconnecting means 23 controls the switch 25 such that it opens anddisconnects the electrical path 26 from the battery stack 11 with thefault to the load 20. The battery stack 11 without the fault becomesresponsible for supplying electrical energy, for example, for continuedoperation or alarming. Examples of faults include: a battery stack 11that provides no output voltage, a battery stack 11 that provide anoutput voltage below a pre-defined threshold, stored in the control unit21 or the control subunits 22, or a failure of a battery connection.

The energy distribution among the battery stacks 11 may be, for example,50/50, i.e., each of the battery stacks 11 provides 50 percent ofelectrical energy required by the load 20. If the load 20 comprisesseveral sub-loads, the sub-loads may be allotted to the battery stacks11 to maintain the desired energy distribution. Furthermore, the energydistribution among the battery stacks 11 may be different andasymmetric, for example, 95/5, where one of the battery stacks 11provides 95 percent of the electrical energy and the other of thebattery stacks 11 provides 5 percent. A battery stack 11 supplying a lowamount of electrical energy (e.g., 5 percent) may serve as an emergencyenergy supply for triggering an alarm in case of a fault. Theelectronics (not shown in FIG. 9) of the load 20 may be designed suchthat it can alternatively access each or both of the battery stacks 11while determining their respective output voltages.

Referring now to FIG. 10, a charging station 30 according to theembodiments described herein is schematically depicted. The chargingstation 30 may be utilized for charging an energy supply 5.1, 5.2, 5.3,5.4, 5.5, 5.6, 5.7, 5.8, 5.9 (FIGS. 1 through 9) of a medical device1.1, 1.2, 1.3. For example, the charging station 30 and a medical device1.1, 1.2, 1.3, as described herein, may be combined to make a medicalsystem. In one embodiment, the charging station 30 comprises an energysupplying means such as, for example, a USB-plug 31, a line connector 32(e.g., a network connector or a 110-230 VAC/DC plug for supplying 110 to230 Volts of alternating current to direct current plug), a solar cellpanel 33, a primary battery 34 (e.g. an AA battery, an AAA batteryand/or a 9 Volt block battery) and a plug 35 for a car cigarette lighteroutlet (i.e. an 12 Volts of direct current (VDC) car plug). The chargingstation 30 comprises a charge slot 36 for the energy supply 5.1, 5.2,5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9 which is connected or connectable tothe USB-plug 31, the line connector 32, the solar cell panel 33, theprimary battery 34, the plug 35, or a combination thereof via a chargingcircuit (not depicted in FIG. 10).

By providing several different types of energy supplying means, the useris not restricted to one type of energy (e.g. a primary battery 34) butcan switch to a different type of energy (e.g. solar energy if the solarcell panel 33 is exposed to sunlight or car battery if the chargingstation is connected with a car) which is available at the particularmoment. The capability to switch between different types of energy mayenhance the independency of the embodiments described herein frompurchasable primary batteries and may increase energy availability innon-everyday situations such as vacation or travel.

The charging station 30 may further comprise a storage slot 37 forstoring an energy supply 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9(FIGS. 1 through 9). For example, an energy supply may be stored suchthat it remains in a desired charge condition, in particular, basicallyfully charged. The storage slot 37 is connected or connectable to theenergy supplying means. An energy supply 5.1, 5.2, 5.3, 5.4, 5.5, 5.6,5.7, 5.8, 5.9 stored in the storage slot 37 may be kept at its nominalcell voltage (e.g. between about 3.0 and about 3.7 Volts) through chargepreservation. The electrical energy required for maintaining the nominalcell voltage is provided by the USB-plug 31, the line connector 32, thesolar cell panel 33, the primary battery 34, the plug 35, or acombination thereof of the charging station 30. A control circuit (notdepicted in FIG. 10) may cooperate with the storage slot 37 forcontrolling the charge of the stored energy supply such that its nominalcell voltage does not fall below a voltage (e.g., about 3.0 Volts and iswithin range of the desired storage voltage (e.g., about 3.7 Volt). Inanother embodiment, the nominal cell voltage is maintained in a propercharge condition by the charging circuit. For example, the chargingcircuit may supervise the voltage of the energy supply 5.1, 5.2, 5.3,5.4, 5.5, 5.6, 5.7, 5.8, 5.9 after having it charged in order to ensureproper/desired storage condition.

The charging station 30 may further comprise a display (not depicted inFIG. 10) for displaying the actual charge of an energy supply insertedinto the charge slot 36 and/or the storage slot 37. Furthermore, thecharging station may comprise more than one of the charge slots 36and/or more than one of the storage slots 37. For example, there may beone display for each of the charge slot 36 and the storage slot 37. Therespective displays may be arranged directly above the correspondingcharge slot 36 and storage slot 37, and the corresponding stored energysupply for providing information regarding the charged energy supply.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the embodiments describedherein without departing from the spirit and the scope of the claimedsubject matter. Thus, it is intended that the specification cover themodifications and variations of the various embodiments described hereinprovided such modifications and variations come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method of monitoring and controlling an energysupply of a medical device, the energy supply comprising a batterycomprising at least two battery stacks, wherein one of the at least twobattery stacks is a backup energy source, said method comprisingproviding the medical device with a control unit which monitors andcontrols the energy supply such that when the control unit detects afault in the at least two battery stacks, the control unit disconnects afaulty battery stack of the at least two battery stacks and uses thebackup energy source, and with a reservoir for a fluid, the reservoircomprising a capacity, wherein the capacity of the reservoir andremaining running time of the energy supply are synchronized such thatchange or refill of the reservoir is required at the same time as changeor recharge of the energy supply.
 2. The method of claim 1 whereinproviding the medical device further comprises providing the medicaldevice with each of the at least two battery stacks with a cover.
 3. Themethod of claim 1 wherein providing the medical device further comprisesproviding the medical device with the at least two battery stacksdisposed in one common cover.
 4. The method of claim 1 wherein providingthe medical device further comprises providing the medical device withthe at least two battery stacks separated by a sealing sheet.
 5. Themethod of claim 1 wherein providing the medical device further comprisesproviding the medical device with the at least two battery stackspositioned side-by-side or on top of each other.
 6. The method of claim1 wherein providing the medical device further comprises providing themedical device with the at least two battery stacks accommodated in anenergy supply housing.
 7. The method of claim 1 further comprisesreplacing the energy supply.
 8. The method of claim 1 further comprisesmeasuring and evaluating an output voltage and/or current of each of theat least two battery stacks with the control unit.
 9. The method ofclaim 1 wherein providing the medical device further comprises providingthe medical device with a control subunit for each of the at least twobattery stacks, such that each control subunit is associated with one ofthe at least two battery stacks and comprises the means for measuringand evaluating the output voltage and/or current of an associatedbattery stack and means for disconnecting the associated battery stack.10. The method of claim 1 wherein providing the medical device furthercomprises providing the medical device with a protection circuit forprotection of each of the at least two battery stacks from overcharge,over-voltage, under-voltage, or a combination thereof.
 11. The method ofclaim 1 wherein providing the medical device further comprises providingthe medical device with a fuel gauge unit for estimating the remainingrunning time of the energy supply.
 12. The method of claim 1 whereinproviding the medical device further comprises providing the medicaldevice with the reservoir being carried by the energy supply.
 13. Themethod of claim 1 wherein providing the medical device further comprisesproviding the medical device with a cavity in the energy supply foraccommodating the reservoir, and accommodating in the cavity thereservoir.
 14. The method of claim 1 wherein providing the medicaldevice further comprises providing the medical device with a housing forthe energy supply and enclosing or carrying the reservoir with theenergy supply housing.
 15. The method of claim 1 wherein providing themedical device further comprises providing the medical device with ahousing, wherein at least a part of the housing of the medical device isformed an energy supply housing.
 16. The method of claim 1 whereinproviding the medical device further comprises providing the medicaldevice with a rechargeable energy supply.
 17. The method of claim 1wherein providing the medical device further comprises providing themedical device with the battery being a lithium-ion polymer battery. 18.The method of claim 1 wherein providing the medical device furthercomprises providing the medical device with each of the at least twobattery stacks comprise a positive potential terminal, a negativepotential terminal and one or more battery cells.
 19. The method ofclaim 1 further comprises providing a charging station for charging theenergy supply, wherein the energy supply is rechargeable, and thecharging station comprises an USB-plug, a line connector, a solar cellpanel, a primary battery, a plug for a car cigarette lighter outlet, aconnector for a mobile phone accumulator, a dynamo, or a combinationthereof for supplying energy.
 20. The method of claim 19 furthercomprises storing the energy supply in a storage slot of the chargingstation such that it maintains a desired charge.